package com.heima.gateway.filter;

import com.alibaba.fastjson.JSON;
import com.heima.gateway.utils.AppJwtUtil;
import io.jsonwebtoken.Claims;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.annotation.Order;
import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.stereotype.Component;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;


@Component
@Slf4j
@Order(-1)
public class AuthorizeFilter implements GlobalFilter {
    private static List<String> urlList = new ArrayList<>();
    // 初始化白名单 url路径
    static {
        //登录
        urlList.add("/login/in");
        //接口文档路径
        urlList.add("/v2/api-docs");
    }

    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        //判断请求是否时白名单路径 (登录)
        ServerHttpRequest request = exchange.getRequest();
        ServerHttpResponse response = exchange.getResponse();
        String reqUrl = request.getURI().getPath();
        for (String url : urlList) {
            if (reqUrl.contains(url)){
                //如果是直接放行
                return chain.filter(exchange);
            }
        }
        //获取请求头中的token信息
        String token = request.getHeaders().getFirst("token");
        if(StringUtils.isBlank(token)){
            //如果token不存在 直接返回401
          return   writeMessage(exchange,"登录已失效,请重新登录");
        }
        //基于Jwt工具类解析token
        try {
            Claims claims = AppJwtUtil.getClaimsBody(token);
            int verifyToken = AppJwtUtil.verifyToken(claims);
            //  -1：有效，0：有效，1：过期，2：过期
            //判断令牌是否失效
            if(verifyToken>0){
                return writeMessage(exchange, "认证失效，请重新登录");
            }
            //解析成功 获取token中的userId
            Object id = claims.get("id");
            //将userId 重新设置到请求头中
            request= request.mutate().header("userId", String.valueOf(id)).build();
            exchange = exchange.mutate().request(request).build();
            //放行请求
            return chain.filter(exchange);
        }catch (Exception e){
            // 如果解析失败  直接返回401 未登录
            return writeMessage(exchange,"认证失效,请重新登录");
        }
    }

    /**
     * 返回错误提示信息
     * @return
     */
    private Mono<Void> writeMessage(ServerWebExchange exchange, String message) {
        Map<String, Object> map = new HashMap<>();
        map.put("code", HttpStatus.UNAUTHORIZED.value());
        map.put("errorMessage", message);
        //获取响应对象
        ServerHttpResponse response = exchange.getResponse();
        //设置状态码
        response.setStatusCode(HttpStatus.UNAUTHORIZED);
        //response.setStatusCode(HttpStatus.OK);
        //设置返回类型
        response.getHeaders().setContentType(MediaType.APPLICATION_JSON);
        //设置返回数据
        DataBuffer buffer = response.bufferFactory().wrap(JSON.toJSONBytes(map));
        //响应数据回浏览器
        return response.writeWith(Flux.just(buffer));
    }
}
